None other than Capt. James T. Kirk once said that space is “the final frontier.” Many scientists have noted that the depths of the ocean, not space, represent the true last frontier in man’s explorations. But in recent years, some of our most remarkable scientific discoveries have come in our growing knowledge of the human body. We’ve mapped the human genome, made breakthroughs in fighting diseases, and gained new insights into how we develop, age, and eventually die. Here are a few mind-boggling numbers highlighting the incredible nature of the human body.
122: Age of Oldest Documented Human
Through the years, a number of people have come forward claiming to be 115 years old or even older, but many of those claims are eventually debunked. No one would have the audacity to come forward claiming to be 122 years old, which is how old Jeanne Louise Calment was when she died in 1997. Calment lived her whole life in France, and her age was well-documented, which led to her fame as a case study in the study of “supercentenarians.” Longevity ran in Calment’s family; her father died at age 93, and an older brother lived to age 97. She remained active well into her later years, riding a bicycle until age 100. But Calment had her bad habits, too — she reportedly ate two pounds of chocolate each week, and smoked until age 117(!) Pity the poor 47-year-old investor who agreed to pay the then-90-year-old Calment a monthly allowance, with the agreement he would take possession of her residence upon her death; he was still paying when he died at age 77.
60,000: Miles of Blood Vessels in the Human Body
Each minute, your heart beats around 75 times, sending billions of red and white blood cells and platelets streaming through a 60,000-mile network of arteries, veins and capillaries. That vast network, if stretched end to end, would be enough to circle the Earth 2 ½ times. When you consider that capillaries are not much wider than a red blood cell, you can see how you’d come up with that incredible 60,000-mile figure.
150,000: Number of Hairs on a Human Head
This seems like a huge number to everyone except men who are going bald. Interestingly, this estimate is for people with blonde hair. Those with brown hair (110,000 hairs), black hair (100,000) and red hair (90,000) don’t fare as well in the count. We could not find research explaining this difference. By the way, those figures dwarf the number of eyebrows (600) and eyelashes (420) found on the typical human body. Here’s a great Harvard University site, B10NUMB3R5, featuring these numbers and many other strange facts about the human body.
100 Trillion: Bacteria Living on and Inside Each Human
If that number sounds terrifying, consider this: Bacteria cells outnumber human cells in your body, roughly 10-1. Before you start squirting hand sanitizer all over your hands and body, understand that the vast majority of these bacteria are essential for maintaining good health. Bacteria in your intestines are essential for the digestion of food. Other bacteria aid in the production of Vitamin K, which is needed to make blood clot. Research announced in 2012 by the University of Pennsylvania revealed that these beneficial bacteria might be critical in helping defend against viral infections. If anything, doctors sometimes worry that there are too few bacteria in your body, which is why you might be told to eat probiotic yogurt, for example, while taking antibiotics. Ongoing research in this area is studying possible benefits that these probiotic treatments might have in battling irritable bowel syndrome and other conditions.
500 Trillion: Synapses in the Human Brain
There’s obviously no way for an accurate count on this, which is why neuroscientists can only estimate there are anywhere from 100 trillion to 500 trillion synapses in the typical human brain. These connections between neurons are critical for brain function, especially in the areas of learning and memory. Deterioration or loss of these synapses has been linked to dementia and other cognitive declines. The good news? Research has shown that older adults who take on challenging new activities, such as learning a new language, or learning to play a musical instrument, can actually strengthen their synapses. Even reading, working a puzzle or socializing can be beneficial in maintaining a healthy brain.